there is a bug with the "Save Identity" Function:
When you select "Settings / CD & Hard drives / Add Hard Drive ... / Read Identity / Save" you get a file-select-dialogbox "Select geometry file".
The path in this dialogbox is preselected with the path where my .hdf- and .geo-files live. I select an existing file, say test.geo, and click on save. All seems well, but it turns out, the path and the selected filename were ignored! The file is saved where the winuaebootlog.txt lives with a filename constructed from drive manufacturer, name and serial and the selected file test.geo is unaltered.

Now indirect uae boot rom address space (upper 64k which has trap data area) is forced to not cache anything. Now it also works without MMU but data cache enabled.

Thanks, it works on my config without pre-MMU setup
(so I can enable/change/test MMU code in every situation when I boot from FS ROM)

Just for the record, I sorted out my previous problems: a Setpatch/MuLibs conflict (so I know how to replicate WinUAE 'bad' crash).

I was using OS3.9 with a BoingBag Setpatch (v44.38).
MuLibs on install declare that can patch Setpatch v44.xx editions but effectively v44.38 in not recognized/patched and for some reason 68030.library is not updated.
So I temporary copied Setpatch 43.7, updated MuLibs and restarted: a 'hybrid' 3.1 start and use the dummy 680x0.library that call the right needed library, but the system somehow works.
Now I re-copied the v44.38 setpatch and rebooted: the system works in OS3.9 mode and MMU works because v44.38 call directly 68030.library (only with a forced DataCache Burst mode enabled but can be easily disabled)..

Toni, so to replicate crash (tested): use OS3.9, use Setpatch v44.38, temporary rename 68030.library (so unused), reboot, the system crash (justly), click 'reboot' or 'suspend' and WinUAE get totally stuck and you need to remove process from task manager.
Or simply ignore this corner case and live happy

Hi Toni, a new interesting bug for you
I'm debugging some stupid code that make illegal access in 24bit memory.
I see with my eyes the illegal access but WinUAE debugger do not trigger (if you remember something similar reported in an old message but i was not able to replicate it, driving me crazy ).

Well, now i'm able.
Use my attached config (or other with z2 mem).
Open debugger: "w 0 800000", then "m 800000" and a magic 200000 mirroring appear at this location . Now "w 0" and no more mirroring.